Put the eggplant pieces in a colander and sprinkle with 2 teaspoons of kosher sea salt. Toss. Set aside for 1-2 hours, this will draw out the excess moisture. When you are ready to sauté the eggplant, spread the pieces out on a tea towel or paper towel and blot off the moisture and salt. Give them a gentle squeeze to remove any remaining moisture.
Heat 1-2 tablespoon extra virgin olive oil in a 12-inch sauté pan over medium heat. When the oil is warm, add the garlic and sauté for about 3 minutes or just when it starts to turn a light golden color.
Add the Italian sausage to the pan, breaking it up into small pieces as the the meat browns. When the meat is browned, remove the sausage with a slotted spoon.
If the pan looks dry, add another 1-2 tablespoons of extra virgin olive oil. Increase the heat to medium-high and add the eggplant pieces in a single layer (this will take several batches to cook). Sauté the eggplant stirring and tossing to brown all the sides. Cook until they are golden and tender, about 8-10 minutes per batch.
Add the tomatoes, oregano, and Piment d' Espelette, salt and pepper. Sauté stirring until the tomatoes start to break down and a juicy sauce develops. Add the browned sausage back to the pan and stir to combine.
Meanwhile, bring a large pot of water to a boil and add 2-3 good pinches of salt. Add the rigatoni and cook 1 minute less than what the package recommends. Reserve 1 cup of the pasta water.
Drain the pasta and add it to the eggplant mixture. Stir and cook for another 1-2 minutes to combine. Add half of the parmesan cheese and stir. If the mixture is too dry stir in a little pasta water.
Serve with remaining parmesan cheese and freshly ground black pepper.